Test And Analysis On Performance Of Rubber Bearing And Seismically Isolated Building

In recent years, seismic isolation technology has been used widespread, and more researchers have focused on some new isolation systems such as hybrid and smart isolation systems. The main work of this paper can be divided into three parts: 1) a brief review of the different analysis models of isolation bearing, the analysis theory and test research for the horizontal stiffness of serial system of rubber bearing with column and composite isolator; 2) the shaking table tests of lead-plug rubber bearing isolation system (LRB system) under multi-dimension ground motion; 3) the shaking table tests of intelligent isolation system consisting of magnetorheological damper (MR damper) and rubber bearing. The primary innovative contents and progress are included as following:1. Based on the summary and discussion of the characteristic features and applicability of the analysis models of isolation bearing and damper, the author emphasized on the calculation method of the horizontal stiffness characteristic of serial system of rubber bearing system with column and composite isolator and gave the analysis results of the effects of typical parameters. The results of numerical calculation show that, the practice of using rubber bearing in serial with structural column is feasible in terms of the small deformation of the column, and when using some rubber bearing of big diameter the application of composite isolator composed of a big isolator and a small one in series would improve the seismically isolated effect during the minor earthquake.2. Experimental research on the vertical and horizontal properties of composite lead-plug isolator has been made, and the characteristic comparison between single and composite isolator, including vertical stiffness and equivalent horizontal stiffness, equivalent damping ratio and horizontal post-yield stiffness, lead to a conclusion that the stiffness of the composite isolator are mainly relied on that of the small isolator and the damping ratio mainly on that of the large one. The investigation show that, to a certain extent, the lead plugged in the rubber beating increases the shear stiffness of the bearing and at the same time have few effect on the bending rigidity, and furthermore we proposed a corrected formula of the horizontal stiffness of composite isolator in consideration of the effect of core lead. The proposed formula was verified by load and deformation test.3. The shaking table tests of a 1/2 scaled 3-strorey steel model of LRB system under multi-dimension ground motion were designed and complemented. According to the test results, the influence of vertical and three directional earthquake wave input at different level on the horizontal isolation performance of LRB system was also explored. The results show that the effect of multi-directional earthquake input waves on the horizontal isolation performance could be negligible at elastic design level, but for design basic and maximum considered earthquake such kind of effect should be appropriately considered.4. The analysis method of the response of the composite horizontal isolation system consisting of MR damper and rubber bearing was discussed, and the control law based on the Classic Optimum Control (COC), Instantaneous Optimum Control (IOC) and Linear Quadratic Gaussian (LQG) algorithms was proposed. Then the performance test of MRF-04K damper was investigated and in result the mechanical parameters were verified.5. The shaking table tests of a 1/2 scaled 3-strorey steel model of hybrid isolation system under one-directional horizontal ground motion were designed and carried out. The author also investigated the horizontal isolation effectiveness of passive and semi-active intelligent control system, the validity of the compound isolation system consisting of MR damper and rubber bearing, and verified the efficiency of the three control algorithm.6. A example of seismic isolation and energy dissipation building was used to illustrate the feasibility and reasonability of the application of compound seismic isolation and energy dissipation technology. At the same time, the optimization option of isolator and damper, the performance test and construction technique were also discussed deliberately. This case study shows that the compound technology will be able to be broadely used in large buildings in the future.